Vestibular System

Question 1

The ________ network controls eye movements to maintain gaze while head is in motion, while the ______ network influences postural adjustments of the head and body

Answer 1

vestibuloocular network, vestibulospinal network

Question 2

The ______ network provides conscious perception of motion and spatial orientation

Answer 2

vestibulothalamocortical network

Question 3

The _____ and the _____ merge to form the vestibulocohlear nerve, CN VIII

Answer 3

vestibular nerve, cochlear nerve

Question 4

The vestibule of the bony labyrinth contains the _____ and the _____

Answer 4

utricle, saccule

Question 5

The sensory organ of the semicircular ducts is the _______ contained in the ______

Answer 5

crista ampullaris, ampullae

Question 6

The otolith organs, utricle and saccule, in vestibule contain ______ as their sensory organ

Answer 6

macula

Question 7

The ______ transduce linear acceleration and tilt

Answer 7

otolith organs (utricle and saccule)

Question 8

The ______ is found between the bony labyrinth and membranous labyrinth and has a high ______ concentration and low _____ concentration

Answer 8

perilymph, Na+, K+

Question 9

The perilymph is continuous with the subarachnoid space via the _______

Answer 9

cochlear aqueduct

Question 10

The _______ is within the membranous labyrinth and is high in ________ and low in ______

Answer 10

endolymph, K+, Na+

Question 11

The ampullae of the semicircular ducts and the utricle and saccule are located in the _______

Answer 11

membranous labyrinth

Question 12

The stereocilia of hair cells of the crista ampullaris are embeded in _________

Answer 12

gelatinous cupula

Question 13

The stereocilia of hair cells in crista ampullaris are deflected by ___________

Answer 13

endolymph movement of cupula

Question 14

________ or _____ displaces otolith membrane and causes deflection of stereocilia

Answer 14

linear acceleration, tilt

Question 15

The otoconia of the macula of the utricle and saccule are _____ dense than the surrounding endolymph

Answer 15

more dense

Question 16

The ______ forms a thickening of the surface ectoderm and invaginates to form otic pit

Answer 16

otic placode

Question 17

The otic placode is a thickening of the _______

Answer 17

surface ectoderm

Question 18

The ________ closes off to form otic vessicle

Answer 18

otic pit

Question 19

The ________ ganglion will eventually split into vestibular (scarpa’s) ganglion and cochlear (spiral ganglion)

Answer 19

statoacoustic ganglion

Question 20

The vestibular ganglion is also called the ________ ganglion

Answer 20

Scarpa’s ganglion

Question 21

The ________ forms the membranous labyrinth. The dorsal portion forms the _______, ________, and _________

Answer 21

otic vesicle, utricle, endolymphatic duct, semicircular ducts

Question 22

The ventral component of the otic vessicle forms the _____ and ______

Answer 22

saccule, cochlear duct

Question 23

The ________ begin as flattened outpocketings of the dorsal otic vesicle

Answer 23

semicircular ducts

Question 24

The blood supply to the membranous labyrinth is via the ________ which is typically a branch of ______

Answer 24

labyrinthine artery, AICA

Question 25

The _________ artery courses with VIII through the internal acoustic meatus

Answer 25

labyrinthine artery

Question 26

_______ and _______ are embedded in cupula or otolith membrane and are surrounded by endolymph (high K+)

Answer 26

stereocilia, kinocilium

Question 27

________ are contained in support cells of the crista ampullaris and maculae and is surrounded by perilymph (low K+)

Answer 27

vestibular hair cell bodies

Question 28

displacement of stereocilia toward the kinocilium of a vestibular hair cell promotes _______ and influx of ____ from endolymph

Answer 28

channel to open, K+

Question 29

Influx of K+ after hair cell channels are opened causes _________ channels to open leading to the release of _______ and _______

Answer 29

Ca2+ channels, aspartate, glutamate

Question 30

The semicircular ducts are oriented ________ to the utricle and saccule

Answer 30

orthogonal

Question 31

The semicircular ducts are _____

Answer 31

yoked to each other

Question 32

orientation of hair cells in yoked semicircular ducts are _________ in relation to each other

Answer 32

complementary (reversed)

Question 33

A head turn to the left will excite hair cells in the __________ and inhibit hair cells in the _______

Answer 33

left horizontal crista ampullaris, right crista ampullaris

Question 34

The kinocillium in the left horizontal semicircular ampulla is closest to the ______ head

Answer 34

posterior

Question 35

The _______ of the otolith membrane of each macula is what all macular hair cells are oriented relative to

Answer 35

striola

Question 36

_______ hair cells are oriented toward the striola, _______ hair cells are oriented away from the striola

Answer 36

utricular, saccular

Question 37

The _______ make it possible for head tilt or linear acceleration to deflect hair cells in this sensory organ

Answer 37

otoconia

Question 38

biplolar neurons of CN VIII form a ____ which synapses with type I vestibular hair cells, and forms a ______ on type II vestibular hair cells

Answer 38

calyx, synaptic bouton

Question 39

Cells bodies in the ________ ganglion are within the internal acoustic meatus

Answer 39

vestibular (Scarpa’s) ganglion

Question 40

The vestibular nuclei found in the caudal pons are the:

Answer 40

superior, medial, and lateral vestibular nuclei

Question 41

The vestibular nuclei found in the rostral medulla are the:

Answer 41

medial and inferior vestibular nuclei

Question 42

The vestibular nuclei of the caudal pons are supplied by the ________ and _______ arteries

Answer 42

circumferential branches of basilar, AICA

Question 43

The vestibular nuclei in the rostral medulla are supplied by the ______ artery

Answer 43

PICA

Question 44

Saccular primary afferent neurons project to _______ which influences _______ via projections to _______

Answer 44

cell group Y, vertical eye movements, oculomotor nucleus

Question 45

The ______ is the only sensory organ to send direct projections to the cerebellum

Answer 45

vestibular labyrinth

Question 46

The ________ nucleus projects bilaterally to vestibular nuclei

Answer 46

fastigial nucleus

Question 47

The ________ influences eye movements, head movements, and posture

Answer 47

vestibulocerebellar module

Question 48

The fastigial nucleus receives input from the vestibular nuclei via the ________ and ________

Answer 48

fastigiovestibular fibers, juxtarestiform body

Question 49

The fastigial nucleus projects to the ________ and ______

Answer 49

flocculonodular lobe, medial part of vermis

Question 50

The _______ are pathways by which pairs of yoked semicircular ducts and maculae are compared

Answer 50

commissural fibers

Question 51

reflexes and postural control impaired by unilateral lesion of peripheral structures can be restored by ________ through commissural fibers

Answer 51

central adjustment

Question 52

________ axons provide proprioceptive input to the vestibular nuclei and arise from ______

Answer 52

spinovestibular axons, all levels of spinal cord

Question 53

The ________ provide input from visual environment to vestibular nuclei

Answer 53

accessory optic system (small visual system nuclei)

Question 54

________ axons are afferents from the thalamus and cortical regions to the vestibular nuclei

Answer 54

corticovestibular and thalamovestibular axons

Question 55

The vestibulospinal network produces reflexive postural adjustments of the head and body via the _______ and the _______

Answer 55

lateral vestibulospinal tract, medial vestibulospinal tract

Question 56

The lateral vestibulospinal tract of the vestibulospinal network projects to the ________ nucleus

Answer 56

lateral vestibular nucleus

Question 57

The medial vestibulospinal tract of the vestibulospinal network receives projections from the ______ and _______

Answer 57

medial vestibular nucleus, inferior vestibular nucleus

Question 58

The UMN cell bodies in the vestibular nucleus are ipsilateral and responsible for reflexive control of ________ and _______ muscles related to balance and posture

Answer 58

paravertebral muscles, proximal limb extensor muscles

Question 59

The _______ receives no input from the cerebral cortex

Answer 59

vestibulospinal network

Question 60

All 4 vestibular nuclei contralaterally project to the ______

Answer 60

thalamus

Question 61

Primarily the ______ thalamus, especially the _____ receive vestibular nuclei input

Answer 61

posterior, VPL

Question 62

The function of the vestibuloocular network is to:

Answer 62

maintain a fixed gaze on an object while the head is moving

Question 63

VOR:

Answer 63

vestibuloocular reflex (moving eyes to maintain gaze on object during head movement)

Question 64

The 3 nuclei involved in the vestibuloocular network are the:

Answer 64

abducens, trochelar, oculomotor

Question 65

The _______ provides connections between abducens, trochlear, and oculomotor nuclei

Answer 65

MLF

Question 66

The bipolar primary afferent neurons of CN VIII within the vestibuloocular network project to the vestibular nuclei and then to ____________ and ________

Answer 66

contralateral abducens nucleus and MLF